Rubber draft gear



April 26, 1960 D. s. CAMPBELL RUBBER DRAFT GEAR 3 SheetsSheet 1 Filed March 2, 1956 INVENTOR.

April 1960 D. s. CAMPBELL 2,934,216

RUBBER DRAFT GEAR Filed March 2, 1956 3 Sheets-Sheet 3 nitd RUBBER DRAFT GEAR David S. Campbell, Glen Ellyn, IlL, assignor to Cardwell Westinghouse Company, a corporation of Delaware Application March 2, 1956, Serial No. 569,020

6 Claims. (Cl. 213-45) This invention relates to draft gears, and more particularly to draft gears of the rubber spring type.

The principal object of the invention is to provide an oversolid stop that positively limits the maximum compression which may be applied to the gear.

Another object is to provide an improved draft gear arrangement that facilitates assembly and permits the gear to be retained in assembled condition for ease in handling, shipping, and installation.

Still another object is to provide an arrangement that permits the gear to be foreshortened to facilitate its insertion into the draft pocket.

Generally speaking, the arrangement of the present invention houses a plurality of cushioning elements of the rubber pad type within a casing that is open at one end to receive the cushioning elements and also to accommodate a plunger that projects into the casing and bears against the cushioning elements. When loads are applied, the plunger moves inward relative to the casing and compresses the cushioning elements but such movement is limited by an oversolid stop arrangement provided between the casing and a follower associated with the plunger.

The plunger and casing are formed with cooperating portions adapted, when the cushioning elements are sufli ciently compressed, to receive therebetween a suitably shaped retaining key that holds the gear assembled under a predetermined amount of compression. In addition, a temporary shortening device may be inserted between the retaining key and the casing to foreshorten the gear and simplify its mounting in the draft pocket.

. Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings, forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,

Fig. 1 is a horizontal section through familiar parts of a freight car showing the rubber draft gear arrangement applied in the draft pocket;

Fig. 2 is a vertical section of the same;

Fig. 3 is a horizontal section through the gear, with parts broken away, illustrating the retaining key in position;

Fig. 4 is a vertical section through the gear with parts broken away to illustrate the location of the retaining key and shortening device;

Fig. 5 is a view of an assembled gear and is taken looking into the plunger housing;

Fig. 6 is a vertical section taken on the line 66 of Fig. 4;

Fig. 7 is a fragmentary sectional view taken on the line 7-7 of Fig. 5 and illustrating the mounting rela tionship of the retaining key between the casing and plunger housing;

Fig. 8 is a fragmentary sectional view generally similar to Fig. 7 and illustrating the manner and arrangement in which the shortening device is applied;

Fig. 9 is a perspective view of the retaining key; and

' amount of compression.

Fig. 10 is a fragmentary perspective view of one corner of the plunger housing.

Referring now to the drawings and particularly to Figs. 1 and 2, there is shown a rubber draft gear, designated generally as 20, in its applied position within a draft gear pocket. The gear is shown in the familiar surroundings of center sills 21, front and rear stops, designated 22 and 23, respectively, a coupler butt or shank 24 slotted as at 25 to receive a horizontal draft key 26, and having a coupler horn 27 spaced forwardly of a striking plate 28 to allow buff travel of the coupler shank, a coupler carrier iron 29, and a draft gear carrier iron 30. A conventional yoke 31 shown here, for illustrative purposes only, as being of the vertical-plane, horizontal key type encircles the gear 20 and has its side arms 32 slotted, as indicated at 33, to receive the draft key 26. These parts are conventional and are so familiar that no specific description is deemed necessary.

As best seen in Figs. 3 and 4, the gear includes a casing 32 having top, bottom and side Walls, designated 33, 34, and 35 respectively, and defining a generally rectangular cross section. The casing is formed with an open front end 36 and an integral rear wall 37 that spans the rear end of the casing and constitutes an integral rear follower. The cushioning mechanism consists of a series of cushioning elements 39 assembled in stacked relationship within the casing and spaced apart by suitable spacing plates 40. Each cushioning element is of familiar form and consists of a support plate 41 on the opposite sides of which are formed vertically extending bars 42 of 70 to durometer rubber that are suitably interconnected through openings 43 formed in the support plate. Finally the gear includes a thrust member or plunger casting 45, here shown in the form of a housing that telescopes within the casing 32 and compresses the cushioning elements against the rear wall of the casing A front follower 46 of conventional form is disposed between the plunger 45 and coupler 24 and transmits buff loads therebetween.

The parts are shown in their normal position in Figs.

1 and 2, and it will be noted that the cushioning mechanism reacts between the front and rear stops 22 and 23 through the medium of the plunger 45 and front follower 46 and the integral rear follower 37. Upon the application of buff loads, the coupler shank 24 moves the front" follower and the plunger inwardly to compress the cushioning mechanism. The arrangement provides an oversolid stop since the front follower overlaps the marginal wall portions of the open end of the casing for abutment therewith to positively limit the maximum compression of the gear. The oversolid stop protects the rubber cushioning elements against excessive bufl. loads. The arrangement of the parts is such that the front follower abuts the draft gear casing before the coupler horn 27 contacts the striking plate 28.

Maximum comparison of the gear is similarly limited in draft. As the yoke moves outwardly under the influence of draft forces, the casing moves outwardly until its travel is blocked by engagement with the front follower 46 which reacts against the front stops 22.

To simplify the handling, storing, and shipping of the. gear, facilities. are also provided for maintaining the various parts ofthe draft gear in assembled relationship with the cushioning mechanism under a predetermined It should be noted that the free height of the stacked series of cushioning elements actually exceeds the length of the casing so that in assembling the gear the plunger must be forced through the open end of the casing. Thus the cushioning elements and plunger are aligned and compressed against the rear wall of the Patented Apr. 26, 1960 casing until the plunger extends determined extent.

The casing and plunger are formed with cooperating portions that interact through an intermediate retaining key and limit the outward movement 'of-the plunger relative to the casing. For this purpose, the open end of the casing is provided with diagonal lips or shoulders 48 in each of its four corners as best seen in Fig. 5, and therefore the support plates 41 for each of the cushioning elements and the spacer plates 40 are formed with cone spondingly shaped corner portions in order that they may pass through the irregularly shaped opening in the open end of the casing. Similarly, the plunger housing which consists of a base plate 45", an upstanding perimetral wall 59 including diagonally extending lower wall portions 51, and horizontally and vertically extending reinto the casing to a preinforcing walls, designated 52 and 53, respectively, is

formed with a novel retaining key pocket adjacent each of the diagonally extending lips 43 of the casing. These pockets are formed in the bottom of'the open ended corner chambers which are designated 55 and which serve as access passages through which the retainer keys 56, best seen in Fig. 9, may conveniently be inserted and removed.

Each of the corner wall portions is provided with a generally rectangularly shaped openings or passage 58 adjacent the plunger base plate and these openings in cooperation with suitable bosses 59 formed on the inside surface of the base plate define the pockets for the retaining keys.

The retaining key consists of a base pad 59 the op posite ends of which overlap with cooperating portions of the casing shoulder and plunger base plate to maintain the gear in assembled relationship and an auxilitary lug 61 that overlies the pad and engages a portion of the plunger corner wall to hold the retaining key in its pocket.

The retaining key is inserted through the access passage 55 provided by the plunger housing and is positioned so that its locking pad portion 60 projects throug the opening or passage 58 in the plunger corner wall and bears against the oppositely facing inside surfaces of the plunger base plate 49 and easing shoulders 48. The rear end of the locking pad is shown in snug engagement with the retaining boss or lug 59 formed on the plunger base.

plate and this engagement in cooperation with the engagement between the upper portion of the auxiliary ing 61 and the adjacent portion of the plunger corner wall prevents the retaining key from tipping in response to the turning moment to which it is subjected by reason of the fact that the casing shoulder and plunger base plate are in non-overlapping relationship.

In order to insert the retaining key within its pocket, it is necessary that the plunger be advanced somewhat beyond the position in which it is shown in Fig. 7 in order to provide suflicient lateral clearance for inserting the retaining key. Thus, with the parts shifted inwardly as mentioned, and with sufiicient clearance provided by the opening 58 and the retaining lug 59, the retaining key may be inserted through the opening or passage 58 at a slight angle and rotated until the base pad 60 is in flush relationship with the plunger base plate 49. After all of the retaining keys are properly positioned, the parts may be released and the draft gear will be held in assembled relationship. While in the present disclosure retaining keys are shown in each corner, it is not absolutely necessary to use all four keys. For example, two keys located in opposite diagonal corners would suffice if desired.

This novel arrangement for retaining the parts of the draft gear in assembled relationship readily lends itself to the use of a shortening element for temporarily foreshortening the gear in order to simplify its insertion in to the draft pocket. One such shortening device is shown in US. Patent No. 2,713,425, to H. E. Tucker and consists of a handle 63 in the form of a long strip on the 4 end of which is mounted a separator 64 of suitable material that yields when subjected to actual loading impacts but which easily withstands the pressures during han dling, shipping, and installation.

Accordingly, the corner walls 51 are provided with recesses 66 that communicate with the openings 58 and that are sulficiently deep to provide adequate mounting clearance for the shortening device.

The shortening device is shown installed in Fig. 8 and this is accomplished by suitably shortening the gear and then inserting the separator between the base pad 60 of the retainer key and the casing shoulder 48. It is contemplated that only two shortening devices, located in 0pposite corners, will suffice.

It should be understood that the description of the preferred form of the invention is for the purpose of complying with section 112, title 35 of the United States code and that the appended claims should be construed as broadly as the prior art will permit.

7 I claim:

1. A draft gear comprising a casing open at one of its ends'and provided with internal shoulders about its periphery adjacent said open end, said shoulders providing inner abutment faces facing inwardly towards the; other end of said casing, a cushioning mechanism disposed in said casing for expansion and compression lengthwise thereof, a plunger casting projecting through the open end of said casing for compressing the cushioning mechanism, said casting having a transverse base plate at the end thereof adjacent said cushioning mechanism and hollow wall structure upstanding from said base, said wall structure having transverse passages formed therein adjacent said base plate with said passages opening through the wall structure at regions in the casing at least partially inwardly of said inner faces, and retaining keys insertable into the casting through the other end thereof and each disposed in engagement with the base plate thereof to project through one of said passages and engage the inner face thereadjacent to maintain the plunger casting locked 'in the casing with the cushioning mecha nism under a predetermined compression.

2. The arrangement of claim 1 wherein said base plate adjacent each passage is formed with an upstanding internal lug for retaining abutment with the retaining key when such key is in position in its passage 3. The arrangement of claim 2 wherein said retaining keys at the ends thereof within said casting are each formed with an integral upstanding lug for abutting enengagement with the inside surface of said wall structure to prevent tipping thereof when in engagement between the plunger casting and the casing.

4. The arrangement of claim 1 wherein the wall structure of said casting has exterior recesses formed therein outwardly of some of said passages, said recesses communicating with said passages to receive a temporary shortening device that is disposable between the cooperating shoulder and key adjacent each recess.

5. 'A draft gear comprising a casing of generally rectangular cross section open at one of its ends and provided with internal corner shoulders adjacent said open end, said shoulders providing inner abutment faces facing inwardly towards the other end of said casing, a cushioning mechanism corresponding in cross-sectional shape and size'to said open end and disposed in said casing for expansion and compression lengthwise thereof, a plunger casting corresponding in cross-sectional shape and size to said open end and projecting therethrough for compressing the cushioning mechanism, said casting having a transverse base plate at the end thereof adjacent said cushioning mechanism and hollow wall structure upstanding from said base plate, said Wall structure having transverse passages formed therein adjacent said base plate with said passages opening through the wall structure at regions in the casing at least partially inwardly of said inner faces, and retaining keys inser ".ble into the casting through the other end thereof and each disposed in engagement with the base plate thereof to project through one of said passages and engage the inner face thereadjacent to maintain the plunger casting locked in the casing with the cushioning mechanism under a predetermined compression.

6. A draft gear comprising a casing open at one of its ends and provided with internal shoulders adjacent said open end such that the open end is of a non-circular cross-sectional configuration, said shoulders providing inner abutment faces facing inwardly towards the other end of said casing, a cushioning mechanism corresponding in cross-sectional shape and size to said open end and disposed in said casing for expansion and compression lengthwise thereof, a plunger casting corresponding in cross-sectional shape and size to said open end and projecting therethrough for compressing the cushioning mechanism, said casting having a transverse base plate at the end thereof adjacent said cushioning mechanism and hollow wall structure upstanding from said base plate, said wall structure having transverse passages formed therein adjacent said base plate with said passages opening through the wall structure at regions in the casing at least partially inwardly of said inner faces, and retaining keys insertable into the casting through the other end thereof and each disposed in engagement with the base plate thereof to project through one of said passages and engage behind the shoulder thereadjacent to maintain the plunger casting locked in the casing with the cushioning mechanism under a predetermined compression.

References Cited in the file of this patent UNITED STATES PATENTS 2,216,473 Hobson Oct. 1, 1940 2,338,453 Nelson Jan. 4, 1944 2,571,220 Dentler Oct. 16, 1951 2,684,160 Dentler July 20, 1954 2,705,077 Forssell Mar. 29, 1955 2,713,425 Tucker July 19, 1955 2,774,486 Forssell Dec. 18, 1956 2,817,445 Campbell Dec. 24, 1957 

